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Test Code SAU Sialic Acid, Free and Total, Random, Urine


Ordering Guidance


This is a recommended screening test for patients suspected to have a diagnosis of free sialic acid storage disease.

Urine oligosaccharides are also recommended for patients with a suspected diagnosis of sialidosis or galactosialidosis.



Necessary Information


Patient's age is required.



Specimen Required


Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Container/Tube: Plastic, 5-mL urine tube

Specimen Volume: 1 mL

Pediatric Volume: 0.5 mL

Collection Instructions: Collect a random urine specimen (early morning preferred).


Forms

1. Biochemical Genetics Patient Information (T602)

2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.

Useful For

Screening for sialic acid disorders

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Sialic Acid, Free and Total, U

Specimen Type

Urine

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 90 days
  Frozen  90 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

Free Sialic Acid:

≤4 weeks: ≤208 mmol/mol creatinine

5 weeks-12 months: ≤104 mmol/mol creatinine

13 months-18 years: ≤100 mmol/mol creatinine

≥19 years: ≤38 mmol/mol creatinine

 

Total Sialic Acid

≤4 weeks: ≤852 mmol/mol creatinine

5 weeks-12 months: ≤656 mmol/mol creatinine

13 months-18 years: ≤335 mmol/mol creatinine

≥19 years: ≤262 mmol/mol creatinine

 

Total/Free Ratio:

≤4 weeks: 1.94-18.68

5 weeks-12 months: 2.34-13.85

13 months-18 years: 2.63-9.18

≥19 years: 3.35-15.81

 

An interpretive report will also be provided.

Interpretation

An elevated result of total/free sialic acid ratio may be indicative of sialidosis or galactosialidosis.

 

A decreased result of total/free sialic acid ratio may be indicative of free sialic acid storage disorder.

 

Abnormal results or clinical suspicion should be confirmed with biochemical or molecular genetic analysis.

Day(s) Performed

Friday

Report Available

5 to 11 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

84275

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SAU Sialic Acid, Free and Total, U 104657-2

 

Result ID Test Result Name Result LOINC Value
621069 Free Sialic Acid 104658-0
621070 Total Sialic Acid 104659-8
621071 Total/Free Sialic Acid Ratio 104660-6
621072 Interpretation 94423-1
621073 Reviewed By 18771-6